A Meta-analysis of Stent Placement vs. Angioplasty for Dialysis Vascular Access Stenosis.

Dysfunction of arteriovenous fistulas (AVF) and arteriovenous grafts (AVG) contribute significantly to morbidity and hospitalization in the dialysis population. Despite advances in endovascular techniques, the incidence of vascular access stenosis remains problematic. Currently, the role of endovascular stent placement in the treatment of vascular access stenosis is poorly defined. This meta-analysis compares the primary patency rates of stenotic vascular access treated with stent placement vs. angioplasty. We searched Medline for English language publications from 1980 through December 2013, along with national conference proceedings and reference lists of all included publications. Inclusion criteria were a measure of primary patency, secondary patency, or access dysfunction. Studies were excluded if they were not in English or if they included pediatric patients. Ten studies with a total of 860 subjects met the inclusion criteria, including six experimental studies and four observational studies. There was significantly higher overall primary patency in those receiving stent placement than in those treated with angioplasty (pooled relative risk [RR] = 0.79; 95% confidence interval [CI]: 0.65-0.96). The estimate did not differ by study design. The effect of treatment differed significantly (p = 0.001) by the type of stents used, however. In studies including nitinol stents (six studies, 678 patients), 6-month patency was significantly better for stent placement than angioplasty (pooled RR = 0.67; 95% CI: 0.54-0.84), whereas there was no significant differences between stent placement and angioplasty in those studies using bare metal stents exclusively (four studies, 182 patients; pooled RR = 1.09; 95% CI: 0.91-1.32). There was significant heterogeneity between studies (I(2)  = 70.6%; p < 0.0001). Our results suggest that stent placement may confer an advantage over balloon angioplasty in primary patency of dialysis access stenoses.